Increased stiffness of large central conduit vessels has recently emerged as an important risk factor for cardiovascular disease. Abnormalities in conduit vessel stiffness are highly prevalent and are associated with several important clinical conditions including hypertension, diabetes, menopause, and advancing age. Increased conduit vessel stiffness increases load on the heart, promotes atherogenesis and is associated with increased risk for myocardial infarction, stroke and heart failure. A number of interventions show preliminary efficacy in reducing conduit vessel stiffness. However, large-scale clinical research in this arena has been severely limited by lack of a robust, reproducible, validated method for quickly, accurately and noninvasively assessing aortic stiffness. Given the magnitude of the clinical problems associated with increased conduit vessel stiffness, there is a critical need for a noninvasive device that will allow a nominally trained operator to accurately assess aortic stiffness. Cardiovascular Engineering, Inc., proposes to develop a noninvasive, photoplethysmographic device that will allow nominally trained operators to quickly and reproducibly assess central aortic pulse wave velocity, a direct indicator of aortic stiffness. This innovative technology will enable accurate diagnosis and risk stratification in a primary care setting and will facilitate further research aimed at evaluating interventions that may reduce conduit vessel stiffness.